Calling the time function in a C program

I have a program that I needed to create for a homework that is an Operating System Simulator. It's not as cool as it sounds. When I run it,

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  long now ;
 
  srand( system( "time(&now)" ) );

Is supposed to create a value that will initialize the "system clock" ( a static int ).

The program runs and does what it is supposed to, except there is no randomness in the results ( there should be differences in the amount of "time units", which are measured in blocks of time that is affected by this function call I believe.

Anyone help me make sure I'm doing this right? It's supposed to put that random # in the variable "now".

Mar 7 '08 #1

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cdietschrun

I have my entire code if someone wants to read it and tell me why I'm not getting random outputs, that works too.

Mar 7 '08 #2

gpraghuram

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Expert 1GB

I have a program that I needed to create for a homework that is an Operating System Simulator. It's not as cool as it sounds. When I run it,

Expand|Select|Wrap|Line Numbers

long now ;

srand( system( "time(&now)" ) );

Is supposed to create a value that will initialize the "system clock" ( a static int ).

The program runs and does what it is supposed to, except there is no randomness in the results ( there should be differences in the amount of "time units", which are measured in blocks of time that is affected by this function call I believe.

Anyone help me make sure I'm doing this right? It's supposed to put that random # in the variable "now".

are you calling seed() function before calling this?

Raghuram

Mar 7 '08 #3

cdietschrun

No, I'm confused by this whole setup. It is from a book and it is 20 years old and they don't explain their code. Our job is to type it in and get it to work in ANSI C and they throw little things like this in there that I can't quite figure out.

Mar 7 '08 #4

Banfa

9,065

Expert Mod 8TB

are you calling seed() function before calling this?

srand IS the seed function for the PRNG.

Mar 7 '08 #5

Banfa

9,065

Expert Mod 8TB

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long now ;

srand( system( "time(&now)" ) );

This code is not right I think you mean

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  long now ;
 
  srand( time(&now) );

But you should read up on system and time so that you understand exactly what they do.

Mar 7 '08 #6

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Calling the time function in a C program

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